Crowded skies

180m passengers in UK in 2000, up 7% on 1999 Biggest rises at Stansted, up 26%, and Luton, 18% Scottish airports had 11.6% rise

And things look set to get worse as the holiday season reaches its peak. Delays and cancellations seem inevitable.

Over July and August, some six million Britons jet off to the Mediterranean in search of sun. And it's up to increasingly overworked air traffic controllers to guide the planes through the crowded skies over Europe.

All-day rush hour

Laurence King, chairman of the controllers branch of the IPMS union, says fatigue and work-related stress are commonplace.

Waiting for take-off: The surge in flights has led to long delays

''In the past we used to have a summer peak and then a winter lull when you could recharge your batteries. You don't get that any more.

"The winter levels now are about equivalent to the summer traffic of three years ago, so you're going full pelt all the year, and it's beginning to tell."

Not only are the skies full year-round, planes are now coming and going thick and fast around the clock.

"It's becoming a younger person's job - most controllers are planning to retire well before 60," says Mr King, who controls en route flights at Manchester.

Filling the skies

With the system working at near-capacity, aircraft have to stay on the ground until it's safe to fly - in other words, controllers create congestion to avoid air traffic jams.

In the first three months of this year, almost one in four flights in the UK took off more than 15 minutes after the expected departure. That compares to one in 10 flights seven years ago.

Controllers fear airlines will lay off staff to cut costs

To pay for the upgrades needed to keep pace, the government has embarked on a controversial part-privatisation of the national air traffic control system.

A consortium of leading airlines plans to buy a 46% stake, but this has been delayed by a last-minute hitch on price.

At issue is the amount to be invested in a new flight data processing system (to replace the one that broke down last summer) and in the new nerve centre at Swanwick, Hampshire, due to open in January, five years behind schedule.

Cruise control

Although Swanwick has new electronic tools to predict flight paths - and possible trouble spots - to make controllers' jobs easier, the training required takes staff out of circulation.

John Cusack starred as a stressed controller

So how true to life is the film, Pushing Tin, in which macho controllers push themselves - and the air space available - to the limit?

As with any Hollywood concoction, it's something of an exaggeration. Yes, it can be frantic, Mr King says, but controllers have to co-operate, not compete.

"You have to know how the person controlling the sector next to yours is going to react. Air traffic control is like a game of four-dimensional chess, except you're all on the same side."